Experimental research on mechanical behavior of latticed circular tubes reinforced concrete T-shaped columns

Special-shaped column structures might improve residential architectural space effectively, compared with traditional frame structures. However, the widespread special-shaped reinforced concrete (RC) columns present insufficient aseismic behavior with a high axial load ratio and sensitivity to the horizontal loading direction, and have strict limitations in aseismic behaviors, in respect to applicable building height and aseismic fortification intensity, which hampers further generalization and application of special-shaped columns in a high aseismic fortification zone. Special-shaped steel reinforced concrete (SRC) columns behave advantages on the aseismic behaviors over special-shaped RC columns. A kind of T-shaped steel reinforced concrete column with latticed steel tubes in the sectional branch components is introduced. Three series of experimental investigations on the axial, eccentric and hysteretic properties of the columns were conducted. Failure modes and mechanical properties of the specimens were investigated, and the mechanisms of the latticed steel tubes and their improvement for concrete failure mode were also studied. Experimental results reveal that: the tube skeleton bears load as integrity, restricts the bond-slip between the concrete and latticed tubes, and postpones the concrete damage to a certain extent. Compared with the RC columns, the SRC columns present enhancement in resistance and ductility under axial or eccentric loads, and improvement in resistance and energy dissipation capacity under hysteretic loads.